#include <bits/stdc++.h>
using namespace std;
const int maxn = 2005;
int idx[maxn];
int sz[maxn];

void init() {
    for(int i = 0; i < maxn; i++) {
        idx[i] = i;
        sz[i] = 1;
    }
}

int find_root(int x) {
    while(x != idx[x]) {
        idx[x] = idx[idx[x]];
        x = idx[x];
    }
    return x;
}
bool check(int A, int B) {
    return find_root(A) == find_root(B);
}

void unite(int A, int B) {
    int rootA = find_root(A);
    int rootB = find_root(B);
    if(rootA != rootB) {
        if(sz[rootA] < sz[rootB]) {
            sz[rootB] += sz[rootA];
            idx[rootA] = idx[rootB];
        }
        else {
            sz[rootA] += sz[rootB];
            idx[rootB] = idx[rootA];
        }
    }
}
int main() {
    int n;
    cin >> n;
    init();
    vector<pair<int, pair<int, int>>> graph;
    for(int i = 0; i < n - 1; i++) {
        int node = i + 1;
        for(int j = 0; j < n - i - 1; j++) {
            int cost;
            cin >> cost;

            graph.push_back({cost, {i, node}});
            node++;
        }
    }

    sort(graph.begin(), graph.end());

    vector<pair<int, int>> g[maxn];
    for(int i = 0; i < (int) graph.size(); i++) {
        int A = graph[i].second.first;
        int B = graph[i].second.second;
        int C = graph[i].first;

        if(!check(A, B)) {
            unite(A, B);
            g[A].push_back({B, C});
            g[B].push_back({A, C});

        }
    }

    for(int i = 0; i < n; i++) {
        sort(g[i].begin(), g[i].end());

        cout << (int) g[i].size() << " ";
        for(int j = 0; j <  (int) g[i].size(); j++) {
            cout << g[i][j].first + 1 << " ";
        }
        cout << endl;
    }

    return 0;
}